Simplify the trigonometric function

Question

sin^4⁡x-cos^4⁡x
cos^2⁡â-sin^2⁡â=1+2cos⁡â

(1+cot^2⁡x )(cos^2⁡x )=cot^2⁡x

cot^2⁡t/csc⁡t =(1-sin^2⁡t)/sin⁡t (Work on both sides!)
sinècscè- sin^2⁡è=cos^2⁡è

Answer 1

sin^4⁡x-cos^4⁡x = (sin^2 x+cos^2 x)(sin^2 x -cos^2 x

= 1 (sin^2 x - cos^2 x)

= 2 sin^2 x - 1